Surfactants are a large class of organic compounds, their properties are very characteristic, the application is extremely flexible, wide, and has great practical value. Surfactants have been used as emulsifiers, detergents, wetting agents, penetrants, foaming agents, adding solvents, dispersants, suspension agents, cement water reducing agents, fabric softeners, levelling agents, color fixing agents, fungicides, catalysts, water repellents, antifouling agents, lubricants, anti-acid fogging agents, dustproof agents, preservatives, spreading agents, thickening agents, film penetrating agents, flotation agents, leveling agents, oil displacing agents, Anti-caking agents, deodorants, antistatic agents, surface modifiers and other dozens of functional reagents are used in daily life and many industrial and agricultural production fields. In addition to a large number of applications in the detergent industry and cosmetics industry, surfactants are also used as additives or additives for food, dairy, paper, leather, glass, petroleum, chemical fiber, textile, printing and dyeing, paint, medicine, pesticides, film, photography, electroplating, metal processing, mineral processing, new materials, industrial cleaning, construction and other traditional industries, as well as high-tech fields. Although they are often not the main body of the industrial product, they can play a key role in the production of various products. Although its dosage is not large, it can play a key role in increasing product varieties, reducing consumption, saving energy and improving quality.
First, the application of surfactant in the textile industry
Surfactants are widely used in textile industry. For example, in the spinning, spinning, sizing, weaving or knitting, refining (bleaching), dyeing, printing, finishing and other textile processing processes, surfactants or surfactant-based additives should be used to improve efficiency, simplify the process, improve performance and improve quality. In practical applications, surfactants are used as cleaning agents, wetting agents, penetrants, emulsifiers, solubilizers, foaming agents, defoaming agents, smoothing agents, dispersants, levelling agents, retarding agents, color fixing agents, refining agents, softening agents, antistatic agents, waterproofing agents, fungicides, etc. In the textile industry, the earliest application of non-ionic surfactants, although in recent years the proportion of its consumption has gradually declined, but relative to other industrial sectors, its dosage is still very large, widely used as solvent, cleaning agent, wetting agent, dispersant, emulsifier, levelling agent, refining agent, softening agent, antistatic agent and so on. Anionic surfactants are mainly used as cleaning agents, penetrants, wetting agents, emulsifiers and dispersants. Cationic surfactants, because the fibers are more negatively charged and can be firmly adsorbed on the fabric, commonly used as fabric softener, levelling agent, waterproofing agent, antistatic agent and color fixing agent; Amphoteric surfactants are generally used as levelling agents for metal complex dyes, fabric softeners and antistatic agents.
Second, the application of surfactants in leather and fur industry
The process of leather making is very complicated and complicated, from bare skin to finished leather needs to go through many processes. Before tanning, the preparation work should be carried out, such as soaking, liming, enzyme softening, soaking, acid removing and degreasing. After tanning, dyeing, fatting, finishing, etc. All these processes need to use surfactants as additives to promote the physical and chemical effects and processes of each process, shorten the production cycle, improve the quality of leather, and save chemical raw materials.
Fur processing also needs to go through a number of processes, in soaking, degreasing, softening, tanning, bleaching, dyeing, fatting, finishing and other processes also need to use surfactants as additives. Leather must remove animal hair, and fur processing requires that the original structure of the hair is not damaged as much as possible, and the use of surfactants can play a good protective role.
The main functions of surfactants in leather production and fur processing are solubilization, emulsification, wetting, penetration, foaming, defoaming, washing, levelling and color fixing. In each process, the role it plays is different, such as in water immersion, it is mainly required to play a wetting and penetration role; In degreasing, it is required to emulsify, moisten and permeate. In decontamination, it is required to have good solubilization; It is required to have good diffusion, penetration and foam effect in dyeing. In fat adding, it is required to have good emulsifying properties.
Third, the application of surfactants in pulp and paper industry
Paper is made from pulp. Pulp is based on some plants, such as wood, grass, cotton as raw materials, using chemical methods or mechanical methods to remove all or most of the impurities, to obtain pure or nearly pure plant fiber pulp. In addition to cellulose, which is the main component of fiber, pulp also contains hemicellulose, lignin and a small amount of resin, pigment, gum and other substances. As far as papermaking is concerned, cellulose and hemicellulose are the basic components of pulp, and other impurities present in the pulp have an adverse effect on the quality of paper, and should be removed as far as possible in the papermaking process, so chemical auxiliaries are needed in the paper formation process. Chemical auxiliaries can be divided into two categories: process auxiliaries and functional auxiliaries. Process auxiliaries are chemicals that promote and improve the efficiency of the paper forming process and prevent fluctuations and interference, including retention agents, filter AIDS, resin control agents, defoaming agents, forming auxiliaries, preservatives, net and felt cleaning agents; Functional additives are chemicals that improve the performance and quality of the final product, including dry strength agents, wet strength agents, sizing agents, fillers, dyes, whitening agents, softeners, etc.
In the pulp and paper industry, surfactants are widely used as chemical additives in the process of pulping, waste paper deinking, paper manufacturing, finished product finishing, paper processing, waste water treatment, etc., which plays an important role in improving the process, improving product quality, increasing economic benefits, and reducing environmental pollution. For example, surfactants are used as resin removers and dispersants in pulping and as penetrants for wood chips and cotton fibres; It is used as deinking agent in the process of making recycled pulp of waste paper. Used as sizing agent and emulsifier in paper sizing process; Used as a defoamer and felt cleaner in the paper making process; Used as dispersant, defoamer, lubricant, preservative, antistatic agent and emulsifying stabilizer in paper coatings; It is used as softener and wetting agent in thin paper products processing.
The application of surfactants in the food industry
With the progress of science and technology, the development of productivity and the improvement of consumption level, people put forward more and more requirements for food. Food first requires health, safety and nutritional value, followed by good color, aroma, taste, shape and other sensory characteristics. In food processing, storage and variety development, we should not only pay attention to the selection of food raw materials, processing technology and equipment, food packaging and storage methods, but also pay attention to the selection and use of food additives. Surfactant is one of the most important food additives, widely used in all kinds of food production, although its dosage is small, but to improve food quality, develop new food varieties, improve production technology, extend food storage and freshness, improve production efficiency and so on have significant effects.
Surfactants are mainly used in the food industry as food emulsifier, defoamer, sugar additives, cleaning agents and fruit peeling agents, etc. The most widely used is food emulsifier.
Application of surfactants in petroleum industry
In the petroleum industry, surfactants, as oilfield chemicals, are widely used in drilling, cementing, oil production, oil gathering and transportation, tertiary oil recovery and oilfield water treatment, etc., which play an important role in ensuring drilling safety, improving oil recovery, oil quality, production efficiency and economic benefits, as well as equipment protection, reducing gathering and transportation costs and preventing environmental pollution. Nowadays, surfactants have become essential oilfield chemicals in oilfield development.
In all aspects of the petroleum industry, a large number of surfactants are used as emulsifiers, demulsifiers, foaming agents, wetting agents, corrosion inhibitors, viscosifiers, descaling agents, fungicides, etc. It is used to prepare drilling fluid, unsticking fluid, cementing fluid, foam drainage fluid, oil displacement agent, anti-wax agent and paraffin removing agent, wetting and resistance reducing agent, emulsifying and viscosity reducing agent, fracturing fluid, acidizing fluid, bactericide, crude oil demulsifier, point and viscosity reducing agent, drag reducing agent, antioxidant, anti-wear agent, cleaning agent, anti-rust agent, antistatic agent, fuel energy saving additive, etc.
Commonly used anionic surfactants include higher fatty acid salts, naphthenates, alkyl benzene sulfonates, alkyl sulfonates, α-olefin sulfonates, petroleum sulfonates, alkyl sulfates, fatty alcohol polyoxyethylene ether sulfate, alkyl succinate, alkyl phosphate salts, fatty alcohol polyoxyethylene ether phosphate salts, etc.
The commonly used cationic surfactants are aliphatic amine hydrochloride, aliphatic imidazoline acetate, alkyl trimethyl ammonium chloride, alkyl dimethyl benzyl ammonium chloride, imidazoline-type ammonium salt, polyquaternary ammonium salt, dialkyl dimethyl ammonium chloride, alkyl pyridine chloride, alkyl dimethylamine acetate, alkyl dimethylamine acetate, Gemimic Gemini quaternary ammonium salt, polyquaternary ammonium salt, etc.
Common amphoteric surfactants include alkyl betaine, sulfobetaine, imidazoline amphoteric surfactants, etc.
The commonly used non-ionic surfactants are fatty alcohol polyoxyethylene ether, alkyl phenol polyoxyethylene ether, fatty amine polyoxyethylene ether, fatty acylalkylanolamine polyoxyethylene ether, polyoxyethylene polyoxyethylene ether, polyoxyethylene polyoxyethylene propylene block polyethers, glycerol fatty acid ester polyoxyethylene sorbitan fatty acid ester, etc.
6, the application of surfactants in metal processing
In the metal processing industry, surfactants are widely used in metal cleaning, pickling, phosphating and metal turning, milling, planing, grinding, drilling, pressing, drawing, polishing, casting, as well as electroplating and corrosion prevention processes. The use of surfactants in each process can not only improve and simplify the process, reduce labor intensity, but also improve product quality, increase product added value, save raw materials and reduce product costs. Countries are actively developing new surfactants for metal processing and researching surfactant compounding technologies to meet the needs of all aspects of the metal processing industry.
In the metal cleaning process, the use of various kinds of cleaning agents with surfactants as the main components, the cleaning effect is good, not only to remove the oil on the metal surface, but also to clean the hand sweat, inorganic salt and other dirt, and the use of safety, non-toxic, but also to prevent corrosion, save energy, reduce environmental pollution, suitable for mechanized automatic cleaning.
In the metal pickling process, the use of pickling liquid with surfactants can improve the effect of pickling and rust removal, and also play a certain role in the corrosion inhibition of metal. Pickling will produce a lot of acid fog, which will not only affect human health and pollute the environment, but also seriously corrodes the plant and equipment. The use of surfactant to suppress fog is convenient and simple, and the effect is good. The fog-suppressors used in the process are composed of various surfactants.
In the metal phosphating (bluing) treatment process, in the neutralization process of the steel plate after pickling, a certain surfactant is added to the neutralizing solution as an emulsifier to accelerate the neutralization reaction and ensure that the neutralization is complete. Phosphating agents used in phosphating are also added with surfactants, whose main role is to play cleaning, corrosion inhibition and surface conditioning, commonly used surfactants are polyoxyethylene non-ionic surfactants and petroleum sulfonate anionic surfactants compound.
Surfactants are also added to the cutting fluid used in the metal cutting process, which mainly plays the role of emulsification, wetting, lubrication and cleaning, as well as corrosion resistance. The commonly used surfactants are polyoxyethylene non-ionic surfactants, aliphatic amines cationic surfactants, sulfonates and phosphate anionic surfactants.
In the quenching process of metal materials and products, the quenching liquid composed of mineral oil and surfactant can be used to quench, which can make the quenching uniform and the quenching part easy to clean.
Surfactants have been widely used in the metal welding process, such as metal welding before the treatment liquid containing surfactants to be treated, can prevent welding slag splash and splash adhesion, and can improve the welding effect, welding points more firm.
Surfactants are also used extensively in the casting process, which can improve the quality of castings and molds, increase productivity and reduce production costs.
The use of surfactants in the plating process of metal parts can obtain dense microcrystals, so that the coating is bright, smooth, uniform, no pinholes, no pitting, the coating and the base metal binding force is strong, can significantly improve the quality of castings, but also save electric energy.
7. Application of surfactants in mining and coal industry
After mineral mining, enrichment to a certain grade in order to smelt, produce a variety of metal raw materials. In general, minerals need to be concentrated after mining. There are many methods of beneficiation, such as floating beneficiation (referred to as flotation), extraction beneficiation, membrane separation beneficiation, magnetic beneficiation and microbial beneficiation. Surfactants are widely used as auxiliaries in beneficiation, such as as collectors, foaming agents and regulators in flotation methods.
In coal industry, surfactants are widely used in various production processes as multifunctional auxiliaries. Such as can be used as coal slime flotation agent, dehydrating agent, dust removal agent, inhibitor, flocculant, coal water slurry and oil coal slurry dispersant, wetting agent and stabilizer.
8. Application of surfactants in coating industry
Coating refers to a coating engineering material that is applied to the surface of an object and can form a film with protection, decoration or special properties. What is commonly known as paint is a type of paint. Coating has many functions: in daily life, housing construction, wood furniture, daily industry, etc., with bright colors to paint, play a decorative role, can give the object to the feeling of beauty, improve its commodity value; Coating of building materials, wood, metal, etc., with paint, play a protective role to increase the durability of the item and prevent corrosion; Coatings are used as color signs, traffic signals, dangerous goods signs, etc. Different compositions of coatings can also play a variety of special roles, such as fire, moisture, mildew, camouflage, discoloration, heat preservation, radiation, gas pollution and so on.
Coatings are generally composed of four major raw materials: film forming substances, pigments, solvents and additives. Film forming material is the basis of coating. Pigments are generally fine powder-like colored substances; In addition to solvo-free coatings, all kinds of liquid coatings generally contain solvents. Currently, the components used as paint solvents include water, aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, esters, ethers, ketones, terpenes, chlorinated organic compounds, etc. Auxiliaries are the auxiliary components of coatings, auxiliaries are generally surfactants, and play a very significant role in coatings.
According to the role of coating, coating surfactants can be divided into the following types:
(1) In the process of coating production: defoamer, wetting agent, dispersant, emulsifier, etc.;
(2) Paint storage process: anti-skinning agent, anti-precipitation agent, etc.;
(3) coating construction film: drier, curing agent, leveling agent, anti-flow hanging agent, etc.;
(4) Effect on the performance of the coating film: plasticizer, smoothing agent, anti-mildew agent, flame retardant, anti-static agent, UV absorber, etc.
9. Application of surfactants in nanomaterials
Nanomaterials science is a new and rapidly developing science, and is one of the hot spots in materials science research in recent years. Surfactants are amphiphilic molecules composed of hydrophobic and hydrophilic parts with different properties. Due to the hydrophobic effect of the amphiphilic molecular structure in the solution, the surfactant molecules can be orderly arranged to form the ordered assembly of various surfactant molecules under certain conditions. The ordered assembly of amphiphilic molecules is the basis of the basic structural unit of life, and it is also an important means to prepare functional materials or realize the functionalization of some chemical substances. In recent years, scientists have used various molecular ordered assemblages formed by surfactants in solution (such as micelles, reverse micelles, microemulsions, lyotropic liquid crystals and vesicles, etc.) as reaction media or templates, which can effectively regulate the size and morphology of nanoparticles, among which the "pool" formed by the reverse micelle as a microreactor is a special nanospace
